System and method for providing a quiet zone

ABSTRACT

A system and method for quieting unwanted sound. As a non-limiting example, various aspects of this disclosure provide a system and method, for example implemented in a premises-based or home audio system, for quieting unwanted sound at a particular location.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

The present application is related to U.S. application Ser. No.14/725,904, filed May 29, 2015, titled “Multi-zone Media System andMethod for Providing Multi-zone Media;” U.S. application Ser. No.14/726,019, filed May 29, 2015, titled “System and Method for ProvidingUser Location-based Multi-zone Media;” U.S. application Ser. No.14/726,109, filed May 29, 2015, titled “System and Method for Selectingand Providing Zone-Specific Media;” and U.S. application Ser. No.14/752,505, filed Jun. 26, 2015, titled “System and Method forIntegrating a Home Media System and Other Home Systems;” the contents ofeach of which are hereby incorporated herein by reference in theirentirety.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

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SEQUENCE LISTING

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MICROFICHE/COPYRIGHT REFERENCE

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BACKGROUND

Present systems and methods for quieting unwanted sound, for example ina premises-based audio system, are inadequate. Further limitations anddisadvantages of conventional and traditional approaches will becomeapparent to one of skill in the art, through comparison of suchapproaches with the present disclosure as set forth in the remainder ofthe present application with reference to the drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure, and are incorporated in andconstitute a part of this specification. The drawings illustrateexamples of the present disclosure and, together with the description,serve to explain various principles of the present disclosure. In thedrawings:

FIG. 1 is a diagram of an example multi-zone media environment, inaccordance with various aspects of the present disclosure.

FIG. 2 is a diagram of an example sound-quieting environment, inaccordance with various aspects of the present disclosure.

FIG. 3 is a diagram of an example sound-quieting environment, inaccordance with various aspects of the present disclosure.

FIG. 4 is a flow diagram of an example method for calibrating a systemto quiet sound, in accordance with various aspects of the presentdisclosure.

FIG. 5 is a flow diagram of an example method for quieting an unwantedsound, in accordance with various aspects of the present disclosure.

FIG. 6 is a diagram of example signal processing for quieting anunwanted sound, in accordance with various aspects of the presentdisclosure.

FIG. 7 is a flow diagram of an example method for counteracting anunwanted sound, in accordance with various aspects of the presentdisclosure.

FIG. 8 is a block diagram of an example audio system component forquieting an unwanted sound, in accordance with various aspects of thepresent disclosure.

FIG. 9 is a diagram of example signal processing for quieting anunwanted sound and/or masking an unwanted sound, in accordance withvarious aspects of the present disclosure.

SUMMARY

Various aspects of this disclosure provide a system and method forquieting unwanted sound. As a non-limiting example, various aspects ofthis disclosure provide a system and method, for example implemented ina premises-based or home audio system, for quieting unwanted sound at aparticular location.

DETAILED DESCRIPTION OF VARIOUS ASPECTS OF THE DISCLOSURE

The following discussion presents various aspects of the presentdisclosure by providing various examples thereof. Such examples arenon-limiting, and thus the scope of various aspects of the presentdisclosure should not necessarily be limited by any particularcharacteristics of the provided examples. In the following discussion,the phrases “for example,” “e.g.,” and “exemplary” are non-limiting andare generally synonymous with “by way of example and not limitation,”“for example and not limitation,” and the like.

As utilized herein the terms “circuits” and “circuitry” refer tophysical electronic components (i.e. hardware) and any software and/orfirmware (“code”) which may configure the hardware, be executed by thehardware, and or otherwise be associated with the hardware. As usedherein, for example, a particular processor and memory may comprise afirst “circuit” when executing a first one or more lines of code and maycomprise a second “circuit” when executing a second one or more lines ofcode. Similarly, the term “module” may be utilized herein to refer to apure hardware module and/or a hybrid hardware/software module (e.g., aprocessor that operates in accordance with software instructions storedin a memory or other non-transitory medium).

As utilized herein, “and/or” means any one or more of the items in thelist joined by “and/or”. As an example, “x and/or y” means any elementof the three-element set {(x), (y), (x, y)}. In other words, “x and/ory” means “one or both of x and y.” As another example, “x, y, and/or z”means any element of the seven-element set {(x), (y), (z), (x, y), (x,z), (y, z), (x, y, z)}. In other words, “x, y and/or z” means “one ormore of x, y, and z.” As utilized herein, the term “exemplary” meansserving as a non-limiting example, instance, or illustration. Asutilized herein, the terms “e.g.” and “for example” set off lists of oneor more non-limiting examples, instances, or illustrations. As utilizedherein, circuitry is “operable” to perform a function whenever thecircuitry comprises the necessary hardware and code (if any isnecessary) to perform the function, regardless of whether performance ofthe function is disabled or not enabled (e.g., by a user-configurablesetting, factory trim, etc.).

The terminology used herein is for the purpose of describing particularexamples only and is not intended to be limiting of the disclosure. Asused herein, the singular forms are intended to include the plural formsas well, unless the context clearly indicates otherwise. It will befurther understood that the terms “comprises,” “includes,” “has,”“comprising,” “including,” “having,” and the like when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another element. Thus, for example, a first element, afirst component or a first section discussed below could be termed asecond element, a second component or a second section without departingfrom the teachings of the present disclosure. Similarly, various spatialterms, such as “upper,” “lower,” “side,” and the like, may be used indistinguishing one element from another element in a relative manner. Itshould be understood, however, that components may be oriented indifferent manners, for example a device may be turned sideways so thatits “top” surface is facing horizontally and its “side” surface isfacing vertically, without departing from the teachings of the presentdisclosure.

Various aspects of the present disclosure comprise a system and methodfor quieting unwanted sound. As a non-limiting example, various aspectsof this disclosure provide a system and method, for example implementedin a premises-based or home audio system, for quieting unwanted sound ata particular location.

The above and other aspects of the present disclosure will be describedin or be apparent from the following description of various exampleimplementations.

FIG. 1 is a diagram of an example multi-zone media environment 100, inaccordance with various aspects of the present disclosure.

The example environment 100 comprises a variety of loudspeakers andgroups thereof, spaced throughout an example premises (e.g., a home,office, campus, etc.). A campus implementation may, for example, includeoutdoor areas as well as indoor areas associated with one or morebuildings. The discussion of various examples herein will often refer tothe example environment 100. Though the example environment 100 isgenerally presented in the context of audio media presentation, itshould be understood that the example environment 100 and all examplespresented herein readily extend to the presentation of other forms ofmedia (e.g., video media).

The example environment 100 may, for example, comprise a first group ofloudspeakers 110, which may also be referred to herein as a zone. Thefirst group of loudspeakers 110 may, for example, correspond to a firstarea (or audio zone) of a premises, for example a family room, mediaroom, etc. The first group of loudspeakers 110 may, for example,comprise a central media controller 111. The central media controller111 may comprise characteristics of any of a variety of central mediacontrollers (e.g., an entertainment center, audio receiver, home mediahub, home audio server, general purpose computer operating in accordancewith software instructions, an Internet media access point or contentserver, etc.). The central media controller 111 may generally, forexample, manage the presentation of media content throughout the exampleenvironment 100. Though the example environment 100 is generally shownand discussed as having a central media controller 111, it should beunderstood that the environment 100 may also operate in a mesh-type ordecentralized configuration. For example, as will be discussed herein,any of the media presentation devices (e.g., loudspeakers, etc.)discussed herein may perform any or all of the control functionalitydiscussed herein.

The first group of loudspeakers 110 may also, for example, comprise afirst (e.g., front left) loudspeaker 112, a second (e.g., front right)loudspeaker 113, a third (e.g., rear left) loudspeaker 114, and a fourth(e.g., rear right) loudspeaker 115. The central media controller 111 mayalso, for example, comprise a loudspeaker (e.g., a center speaker). Eachof the first group of loudspeakers 110 may, for example, be operatedindependently or may be operated as a single group. Each of the firstgroup of loudspeakers 110 may, for example, operate under the control ofthe central media controller 111 and/or operate autonomously. Note thatthe designations of the loudspeakers as left, right, front, rear,center, etc. may, but need not, refer to audio spatial arrangementsgenerally synonymous with various loudspeaker arrangements (e.g.,stereo, surround sound, monaural, etc.).

The example environment 100 may also, for example, comprise a secondgroup of loudspeakers 120. The second group of loudspeakers 120 may, forexample, comprise a first (e.g., right) loudspeaker 121 and a second(e.g., left) loudspeaker 122. The second group of loudspeakers 120 may,for example, correspond to a second area of a premises, for example akitchen or dining room, a break room, etc. Each of the second group ofloudspeakers 120 may, for example, be operated independently or may beoperated as a single group. Each of the second group of loudspeakers 120may, for example, operate under the control of the central mediacontroller 111 and/or operate autonomously. Also for example, any or allof the second group of loudspeakers 120 may operate with any or all ofthe other loudspeakers in the environment 100.

The example environment 100 may additionally, for example, comprise athird group of loudspeakers 130. The third group of loudspeakers 130may, for example, comprise a first (e.g., rear) loudspeaker 131, asecond (e.g., right) loudspeaker 132, and a third (e.g., left)loudspeaker 133. The third group of loudspeakers 130 may, for example,correspond to a third area of a premises, for example a master bedroom,garage, shop, etc. Each of the third group of loudspeakers 130 may, forexample, be operated independently or may be operated as a single group.Each of the third group of loudspeakers 130 may, for example, operateunder the control of the central media controller 111 and/or operateautonomously. Also for example, any or all of the third group ofloudspeakers 130 may operate with any or all of the other loudspeakersin the environment 100.

The example environment 100 may further, for example, comprise aloudspeaker 141 in a fourth area (or room or zone) (e.g., in a masterbath), a loudspeaker 151 in a fifth area (e.g., in a guest bath), aloudspeaker 161 in a sixth area (e.g., in a guest room), and aloudspeaker 171 in a seventh area 170 (e.g., in an office).

Various aspects of this disclosure will be presented by referring toexample sound-quieting scenarios. The example environments 200 and 300shown in FIGS. 2 and 3 may be referred to when presenting such examplescenarios.

FIG. 2 is a diagram of an example sound-quieting environment 200, inaccordance with various aspects of the present disclosure. The exampleenvironment 200 is generally shown with reference to the seventh area170 (or group of loudspeakers) shown in the example environment 100 ofFIG. 1. The seventh area 170 (or zone) may, for example, be associatedwith an office.

The example environment 200, for example, comprises a zone 170 (or areaor room). A user 207 is shown working at a desk 208. The user 207 iswearing an electronic device 209 that comprises sound detectioncapability (e.g., a microphone, a loudspeaker being utilized as amicrophone, etc.). The electronic device 209 may comprisecharacteristics of any of a variety of user wearable and/or carryableelectronic devices (e.g., a smart phone, a mobile phone, a Bluetoothearpiece, a smart watch, smart eyewear, a gaming headset, a fitnessmonitoring device, etc.). Though not shown in the example environment200, the electronic device 209 may also comprise an electronic devicelocated close to (e.g., but not on) the user 207, for example located atthe computing station at which the user 207 is working, incorporated inor mounted to the user's chair (e.g., at a top back or headrest positionthereof), etc. In a bedroom scenario, the electronic device 209 may, forexample, be mounted to a headboard proximate a user's head, or forexample a nightstand, integrated with or mounted to a pillow ormattress, etc.). The electronic device 209 may also, for example, beintegrated with a tabletop or desktop.

In the example environment 200, the electronic device 209 may, forexample, be located close enough to the user to accurately characterizesound (e.g., phase, amplitude, frequency components, etc.) that is beingexperienced by the user. For example, the electronic device 209 may bepositioned within a fraction of a wavelength of a sound near the upperbound of the quieting passband that is quieted by a method or systemdiscussed herein. For example, the electronic device 209 may, forexample, be positioned relative to the user's ear within a tenth orwithin an eighth of the wavelength of the sound that is quieted (e.g.,within 1 foot, within 2 feet, etc.). Performance may, for example, varywith varying distances. For example, the systems and methods presentedherein may still quiet unwanted sound to some extent, even as theelectronic device 209 moves away from the user's ears (e.g., within afourth of a wavelength of the quieted sound). Note additionally, in ascenario in which the spatial relationship between the user 207 and theelectronic device 209 is generally known and consistent (e.g., thespatial relationship between the user's ears and the desk chair orcomputer monitor on which the user 207 works), the electronic device 209may be farther from the user's ears.

In the example environment 200, a sound source 205 generates a sound(e.g., a disturbance sound, or an unwanted sound to be cancelled). Thesound source 205 may be any of a variety of sources of unwanted sound(e.g., a passing truck, a train, a jet, a neighbor's party, etc.).Sounds are generally presented herein as vectors, as in a general sense,such sound signals are vector quantities that may be functions offrequency, amplitude, phase, and may also contain information regardinglocation (e.g., x, y, and z spatial coordinates). Such sound as providedto the user 207 and/or as detected at the electronic device 209 is shownat sound 210. As will be discussed herein, in accordance with variousaspects of this disclosure, the loudspeaker 171 may generate acancellation signal (or anti-noise signal, or counter-sound) thatdestructively interferes with the unwanted sound 210 at the location ofthe user or of the user's ears to quiet the unwanted sound 210. Suchquieting may, for example, be full or partial.

Such cancellation signal as provided to the user 207 and/or theelectronic device 209 is shown at cancellation signal 220. The combinedunwanted sound 210 and cancellation signal 220 as perceived by the user207 is substantially quieter than when just the unwanted sound 210 isperceived by the user 207.

FIG. 3 is a diagram of an example sound-quieting environment 300, inaccordance with various aspects of the present disclosure. The exampleenvironment 300 is generally shown with reference to the third area 130(or group of loudspeakers) shown in the example environment 100 ofFIG. 1. The third area 130 (or zone) may, for example, be associatedwith a bedroom.

The example environment 300, for example, comprises a zone 130 (or areaor room). A user 307 is lying on a bed 308. Though the user 307 may bewearing or carrying an electronic device (e.g., like the electronicdevice 209 shown in FIG. 2 and discussed herein), the user 307 need notbe wearing or carrying such a device.

The example environment 300 comprises a left loudspeaker 133 and a rightloudspeaker 132. In the example scenario, the left loudspeaker 133 isbeing utilized as a sound detector. For example, the speaker of theloudspeaker 133 may be utilized as a microphone, the loudspeaker 133 maycomprise an on-board microphone separate from its speaker(s), etc.Similarly, the right loudspeaker 132 may be utilized as a sounddetector. For example, the speaker of the loudspeaker 132 may beutilized as a microphone, the loudspeaker 132 may comprise an on-boardmicrophone separate from its speaker(s), etc. Note that in variousexample scenarios, speakers may be simultaneously utilized as both soundinput and sound output devices (e.g., when known output sound activitycan be subtracted from monitored speaker activity to determine theremaining speaker activity due to sound impacting the speaker).

The example environment 300 also comprises a loudspeaker 131. As withthe loudspeaker 171 of FIG. 2, in this example, the loudspeaker 131 maybe utilized to quiet unwanted sound as provided to the user 307 (e.g.,and as generated by the source 305).

In the example environment 300, the left loudspeaker 133 and the rightloudspeaker 132 may be utilized to characterize the sound (e.g., phase,amplitude, frequency components, etc.) that is being provided to (orexperienced by) the user 307. For example, sound detected by the right132 and left 133 loudspeakers may be analyzed (e.g., phase and/or timecompared) to estimate the sound being provided to the user 307. Variousexamples of such analysis are provided herein.

In the example environment 300, a sound source 305 (e.g., a primarysource) generates a sound (e.g., an unwanted sound to be cancelled).Such sound as provided to the user 307 is shown at sound 310, such soundas provided to the right loudspeaker 132 is shown at sound 312, and suchsound as provided to the left loudspeaker 133 is shown at sound 314. Aswill be discussed herein, in accordance with various aspects of thisdisclosure, the loudspeaker 131 (e.g., a secondary source) may generatea cancellation signal (or anti-noise signal, or counter-sound) thatdestructively interferes with the unwanted sound at the location of theuser or of the user's ears to quiet the unwanted sound 310. Suchquieting may, for example, be full or partial.

Such cancellation signal as provided to the user 307 is shown atcancellation signal 320, such cancellation signal as provided to theright loudspeaker 132 (now the left loudspeaker from the user'sperspective) is shown at cancellation signal 322, and such cancellationsignal as provided to the left loudspeaker 133 (now the rightloudspeaker from the user's perspective) is shown at cancellation signal324. Though the combined unwanted sound 312 and cancellation signal 322as detected by the right loudspeaker 132, and the combined unwantedsound 314 and cancellation signal 324 as detected by the leftloudspeaker 133 need not be quieted, the combined unwanted sound 310 andcancellation signal 320 as provided to (or as perceived by) the user 307is substantially quieter than when just the unwanted sound 310 isprovided to the user 307.

The example environments 100, 200, and 300 shown in FIGS. 1-3 areutilized herein to illustrate various aspects of the disclosure. Notethat the scope of this disclosure should not be limited by anycharacteristics of the example environments 100, 200, and 300.

To counteract (or cancel) a sound as perceived by a user, in particularvia generation of a cancellation signal by one of more loudspeakers, itmay be beneficial to understand the relationship between a detectedsound and a generated cancellation signal or signal causing thegeneration of such cancellation signal. Though various aspects of thisdisclosure may comprise utilizing various simplifying assumptions (e.g.,perfect sound production by audio circuitry and speakers, perfect soundpropagation from a loudspeaker to a location of interest, noenvironmental effects on sound waves, no echo, etc.), and suchsimplifying assumptions may still result in a beneficial system and/ormethod, characterization of the relationship between a desired sound(e.g., a desired cancellation signal) and the audio signal(s) (e.g.,digital and/or analog signals) necessary to produce the desired soundmay increase the precision with which a cancellation signal isgenerated. Accordingly, various aspects of this disclosure comprise acalibration method and system to identify a relationship between a sound(e.g., a cancellation signal) generated by an audio system and arrivingat the location of interest, and the signal(s) within the audio systemthat cause the generation of such sound. An example of such calibrationis provided at FIG. 4.

FIG. 4 is a flow diagram of an example method 400 for calibrating asystem to quiet sound, in accordance with various aspects of the presentdisclosure. The example method 400 may, for example, share any or allaspects with other example methods presented herein (e.g., with regardto FIGS. 5-8 and other discussions).

The example method 400 may begin executing at block 405. The examplemethod 400 may begin executing in response to any of a variety of causesor conditions, non-limiting examples of which are presented herein.

The method 400 may, for example, begin executing when an audio system(e.g., dedicated audio system, audio presentation portion of a mediapresentation system, etc.) implementing the method 400 is powered up,reset, or turned on. The method 400 may also, for example, beginexecuting when a media presentation system implementing the method 400receives a command from a user to perform a calibration. The method 400may, for example, comprise performing an initial calibration and/or are-calibration (e.g., if a room environment changes, if a calibrationhas been observed the user or the system to work poorly, etc.) Themethod 400 may further, for example, begin executing when a userindicates that test apparatus is operational and/or in a position forcalibration. The method 400 may further, for example, begin executing inresponse to an audio system (e.g., a controller, loudspeaker, etc.)exiting from a sleep mode. Also for example, the method 400 may beginexecuting in response to detecting a user input (e.g., a touch command,a voice command, etc.) at a component of the audio system (e.g., at aloudspeaker, at a controller, at a sensor independent of a loudspeakeror controller, etc.). Additionally, for example, the method 400 maybegin executing in response to detecting a user input at a sensorphysically independent of yet communicatively coupled to an audio systemor a component thereof (e.g., a sensor of a security system, homecontrol system for a smart home, home environmental control system,etc., that is communicatively coupled to an audio system implementingvarious aspects of the method 400). Still further for example, block 405may receive execution flow from any of the blocks of the example method400 and/or from any flow diagram block discussed herein (e.g., at FIGS.5-7). In general, the method 400 may begin executing in response to anyof a variety of causes or conditions. Accordingly, the scope of thisdisclosure should not be limited by characteristics of any particularinitiating cause or condition.

The example method 400 may, at block 410, comprise generating one ormore test stimuli (e.g., test sound, etc.). Block 410 may compriseperforming such test stimuli generating in any of a variety of manners,non-limiting examples of which are presented herein.

For example, block 410 may comprise generating the test stimuli from oneor more speakers that will be used to transmit cancellation signals toquiet unwanted sounds. For example, in the example environment 200 ofFIG. 2, block 410 may comprise generating the test stimuli from theloudspeaker 171. Also for example, in the example environment 300 ofFIG. 3, block 410 may comprise generating the test stimuli from the rearloudspeaker 131. As discussed herein, while the example environments 200and 300 show only one loudspeaker being used for generating thecancellation signals, a plurality of loudspeakers may also be used. In amulti-loudspeaker scenario, the test stimuli may be output from theplurality of speakers that will be used for generating the cancellationsignals.

The test stimuli and/or corresponding signals may comprisecharacteristics of any of a variety of types of test stimuli. Forexample, a test stimulus may comprise a time-domain sweep of frequencies(e.g., frequencies relevant to the band in which sound cancellation willbe performed). For example, in an example implementation in whichunwanted sound up to 400 Hz will be cancelled, the test stimulus maycomprise a sequential sweep of audio frequencies up 400 Hz, up to anoctave above 400 Hz (e.g., 800 Hz), and potentially beyond (e.g., tomitigate phase shift issues and/or other concerns). In an examplescenario, the test stimulus may comprise a sequential sweep of audiofrequencies up to at least an octave beyond the quieting passband. Alsofor example, the test stimulus may comprise pseudo-random noise (e.g.,white noise, pink noise, etc.), for example comprising frequencycomponents relevant to the band in which sound cancellation will beperformed.

The test stimulus may, for example, comprise time-varying amplitude forthe entire sound and/or individual frequency components thereof. Forexample, for a first time period, a first frequency component of thetest stimulus may comprise a first amplitude, and for a second timeperiod, the first frequency component of the test stimulus may comprisea second amplitude, etc.

In the example environment 200 of FIG. 2, block 410 may compriseutilizing the loudspeaker 171 to output the test stimuli. Whilegenerating the test stimulus, the test stimulus as provided to the user207 (or electronic device 209) may be shown as sound 220. In the exampleenvironment 300 of FIG. 3, block 410 may comprise utilizing the rearloudspeaker 131 to output the test stimuli. While generating the teststimulus, the test stimulus as provided to the user 307 may be shown assound 320, the test stimulus as provided to the right loudspeaker 132may be shown as sound 322, and the test stimulus as provided to the leftloudspeaker 133 may be shown as sound 324.

Various aspects of block 410 may, for example, be performed by an audiosystem controller. An example controller 111 is shown in FIG. 1 for apremises or home. The controller may also, for example, be a remotecontroller networked to the environment 100 via a communication network.The controller may further, for example, be a localized controller of anaudio zone (or room or speaker group). In an example implementation, thecontroller may also be incorporated into a loudspeaker enclosure (e.g.,loudspeakers 171, 131, 132, and 133 of FIGS. 2 and 3). The controllermay, for example, control generation of the test stimulus by a localspeaker (e.g., housed in a same enclosure as the controller), by aremote speaker (e.g., separate from the controller and communicativelycoupled to the controller), etc.

In general, block 410 may comprise generating one or more test stimuli.Accordingly, the scope of this disclosure should not be limited bycharacteristics of any particular test stimulus or manner of generatinga test stimulus.

The example method 400 may, at block 420, comprise receiving the one ormore test stimuli. Block 420 may comprise receiving the test stimuli,for example the one or test stimuli generated at block 410, in any of avariety of manners, non-limiting examples of which are presented herein.

For example, block 420 may comprise receiving the test stimuli at thesound sensor that will be used to receive and detect an unwanted signalto be cancelled. For example, as shown in the example environment 200 ofFIG. 2, the electronic device 209 with audio reception capability may beutilized to receive the test stimulus (e.g., shown as sound 220 duringcalibration) output from the loudspeaker 171. For example, block 420 maycomprise receiving the test stimuli at the location or zone to bequieted or close to such location (e.g., within a tenth or an eighth ofa wavelength of sound to be cancelled, etc.).

Also for example, as shown in the example environment 300 of FIG. 3, theleft loudspeaker 133 with audio reception capability may be utilized toreceive the test stimulus (e.g., shown as sound 324 during calibration)output from the rear loudspeaker 131, and the right loudspeaker 132 withaudio reception capability may be utilized to receive the test stimulus(e.g., shown as sound 322 during calibration) output from the rearloudspeaker 131. For example, block 420 may comprise receiving the teststimulus at one or more locations that are substantially different fromthe location to be quieted or outside the zone to be quieted (e.g., morethan a tenth or an eighth of a wavelength of a sound to be cancelled,more than a fourth of a wavelength of a sound to be cancelled, etc.).

Additionally, in a hybrid scenario, block 420 may comprise receiving thetest stimulus at one or more speakers positioned at the location or zoneto be quieted and at one or more speakers positioned outside of thelocation or zone to be quieted.

Block 420 may, for example, comprise communicating information of thereceived sound to a controller (e.g., from a sound sensor at which thetest stimulus was received). As explained herein, such a controller maybe an audio system controller. An example controller 111 is shown inFIG. 1 for a premises or home. The controller may also, for example, bea remote controller networked to the environment 100 via a communicationnetwork. The controller may further, for example, be a localizedcontroller of an audio zone (or room or speaker group). In an exampleimplementation, the controller may also be incorporated into aloudspeaker enclosure (e.g., loudspeakers 171, 131, 132, and 133 ofFIGS. 1-3). The controller may, for example, control generation of thetest stimulus by a local speaker (e.g., housed in a same enclosure asthe controller), by a remote speaker (e.g., separate from the controllerand communicatively coupled to the controller), etc.

Block 420 may, for example, comprise timestamping information of thereceived test stimuli. Such timestamping may, for example, be utilizedby other blocks (e.g., block 430) when determining the relationshipbetween generated test stimuli (or corresponding signals) and thereceived test stimuli.

In general, block 420 may comprise receiving the one or more teststimuli. Accordingly, the scope of this disclosure should not be limitedby characteristics of any particular received test stimuli or by anymanner of receiving a test stimulus.

The example method 400 may, at block 430, comprise characterizing arelationship between the one or more test stimuli as generated at block410, and/or respective audio signals associated with the generationthereof, and the one or more test stimuli as received at block 420.Block 430 may comprise characterizing the relationship in any of avariety of manners, non-limiting examples of which are presented herein.

For example, block 430 may comprise analyzing the test stimuli receivedat block 420 and the generated test stimuli generated at block 410 (orassociated signals causing such sounds to be generated) and determininga transfer function relating them. Block 430 may comprise performingsuch analysis for single aggregate generated test stimuli and receivedtest stimuli and/or may comprise performing such analysis for singlefrequencies and/or frequency bands of interest. In other words, block430 may comprise determining a set of transfer functions for differentrespective frequency bands. Block 430 may comprise determining thetransfer function(s) (e.g., H(s), H⁻¹(s), H(z), H⁻¹(z), etc.) in any ofa variety of known manners. These transfer function(s), for example,relate the time-varying complex acoustic response (e.g., which generallymay also vary in magnitude, frequency, and/or phase of a detected,objectionable acoustic disturbance at the location of a detectiondevice) to that captured, contemporaneously or previously via acalibration routine, at the location of the user's ears and so mayreflect how the acoustic environment of the user's space shapes thedisturbance's acoustic attributes.

Block 430 may, for example, comprise specifying the transfer functionsand/or the implementation thereof in any of a variety of manners. Forexample, block 430 may comprise determining filter coefficients for theefficient implementation of the transfer functions (e.g., as discussedherein with regard to FIG. 5). For example, a single multi-order filter(e.g., composed of several or many poles and zeroes) derived fromseparate bandpass filters, may result in the lowest computationallatency. Filter compilation, by which the coefficients of a singlerepresentative filter are constructed may, for example, be performedduring or immediately after the calibration process (e.g., whensecondary source-to-targeted quiet zone transfer functions arecaptured). Further, FIR (finite impulse response) filters may afford theadditional advantage of linear phase and more precise filter shapes,albeit at the expense of computational processing power.

Block 430 may comprise characterizing the relationship (e.g., transferfunction(s)) to any of a variety of degrees of accuracy. For example,linear and/or low-order non-linear approximations may be utilized tosimply utilization of the transfer function(s), for example trading offpotential accuracy for lower processing speed, lower energy consumption,etc. The relationship determined at block 430 need not be perfect toprovide substantial sound cancellation benefits.

In general, block 430 may comprise characterizing a relationship betweenthe one or more test stimuli as generated at block 410, and/orrespective audio signals associated with the generation thereof, and theone or more test stimuli as received at block 420. Accordingly, thescope of this disclosure should not be limited by any particular mannerof characterizing such relationship, for example by any particularmanner of determining a transfer function characterizing suchrelationship.

The example method 400 may, at block 440, comprise storing informationof the relationship determined at block 430 in a memory. Block 440 maycomprise storing the information of the relationship (e.g., transferfunction information) in any of a variety of manners, non-limitingexamples of which are provided herein.

Block 440 may, for example, comprise storing the information in memoryof a controller or other device that uses such information. As anexample, as discussed herein, transfer function information may beutilized in determining cancellation signal signals that will result inthe desired cancellation signal being presented at a location ofinterest. When needed, the transfer function information may beretrieved from memory.

The example method 400 may, for example, be performed for any of avariety of quiet locations or zones. For example, though only twoexample scenarios 200 and 300 are presented in FIGS. 2 and 3, any of anumber of such scenarios may be included in a system. For example, anyor all of the audio zones in the example environment 100 shown in FIG. 1may comprise a respective one or more locations and/or zones for whichsound quieting services may be provided (e.g., a location or zoneassociated with a user's typical working position at a desk, a locationor zone associated with the user's head when sleeping, a location orzone associated with a favorite recliner used for resting or reading,etc.). Each sound-quieting scenario may have its own respective transferfunction information to be utilized in forming cancellation signals. Therespective transfer function between targeted quiet zones and noisecancelling sources (e.g., loudspeakers) corresponding to a location orzone for which there is a present need for sound-quieting service maythen be retrieved from memory as needed (e.g., based on a databasesearch, by indexing into an array of transfer functions based onlocation, etc.).

Block 440 may, for example, comprise storing the transfer function (orother characterization) information in a central memory (e.g., adatabase local to a premises, a cloud-based database, etc.). Also forexample, block 440 may comprise storing such information in adistributed manner, for example at respective components of each audiozone for which sound-quieting capability is provided.

Block 440 may also, for example, comprise updating transfer functioninformation (or other characterization information) with currentinformation. For example, when the method 400 is repeated for a locationor zone, block 440 may comprise replacing information resulting fromprior calibration activity with results from a present calibration.

In general, block 440 may comprise storing information of therelationship determined at block 430 in a memory. Accordingly, the scopeof this disclosure should not be limited by characteristics of anyparticular manner of performing such storage.

The example method 400 may, at block 495, comprise continuing execution.Such continued execution may comprise any of a variety ofcharacteristics, non-limiting examples of which are presented herein.For example, block 495 may comprise looping execution flow back up toany of the previous blocks of the example method 400 and/or to any flowdiagram block discussed herein.

As discussed herein, various aspects of this disclosure may provide forquieting an unwanted sound at a location or within a zone generallyassociated with a location. Various examples of such operation arepresented herein. The example method 500 of FIG. 5 provides one suchexample.

FIG. 5 is a flow diagram of an example method 500 for quieting anunwanted sound, in accordance with various aspects of the presentdisclosure. The example method 500 may share any or all aspects withother methods discussed herein (e.g., with regard to FIGS. 4 and 6-8,and other discussions). FIG. 6, which is a diagram 600 of example signalprocessing for quieting an unwanted sound, in accordance with variousaspects of the present disclosure, will be referred to during thediscussion of FIG. 5.

The example method 500 may, for example, begin executing at block 505.The example method 500 may begin executing in response to any of avariety of causes or conditions, non-limiting examples of which arepresented herein.

The method 500 may, for example, begin executing when an audio system(e.g., dedicated audio system, audio presentation portion of a mediapresentation system, etc.) implementing the method 500 is powered up,reset, or turned on. The method 500 may also, for example, beginexecuting when a media presentation system implementing the method 500receives a command from a user to quiet unwanted sound (e.g., auser-identified sound, an unwanted sound automatically identifiedwithout present user interaction, etc.). For example, referring to FIG.2, the user 209 may speak a voice command (e.g., speaking the word“quiet”) to trigger sound cancellation operation upon hearing anunwanted noise (e.g., a vacuum cleaner, a passing train, a jet engine,etc.) and/or when beginning to work at the desk 208 (e.g., inanticipation of unwanted sound that has not yet occurred). The userinput may also, for example, be tactile (e.g., pushing a mechanical orgraphical “quiet” button, entering a command to execute an application,etc.). Also for example, referring to FIG. 3, the user 309 may speak avoice command to trigger sound cancellation operation upon hearing anoisy party at a neighbor's house or adjacent apartment and/or whenlaying down (e.g., just in case noise occurs during sleep).

The method 500 may further, for example, begin executing in response toan audio system (e.g., a controller, loudspeaker, etc.) exiting from asleep mode. For example, execution of the method 500 may begin as adefault mode of operation, or may continue if it was executing when thesleep mode began.

The method 500 may begin executing in response to detecting a user input(e.g., a touch command, a voice command, etc.) at any component of theaudio system (e.g., at a loudspeaker, at a controller, at a sensorindependent of a loudspeaker or controller, etc.). Additionally, forexample, the method 500 may begin executing in response to detecting auser input at a sensor physically independent of yet communicativelycoupled to an audio system or a component thereof (e.g., a sensor of asecurity system, home control system for a smart home, homeenvironmental control system, etc., that is communicatively coupled toan audio system implementing various aspects of the present disclosure).

Still further for example, block 505 may receive execution flow from anyof the blocks of the example method 500 and/or from any flow diagramblock discussed herein (e.g., at FIGS. 4 and 6-8). In general, themethod 500 may begin executing in response to any of a variety of causesor conditions. Accordingly, the scope of this disclosure should not belimited by characteristics of any particular initiating cause orcondition

The example method 500 may, at block 510, comprise identifying alocation, for example a location at which an unwanted sound is to bequieted. Block 510 may comprise identifying a location in any of avariety of manners, non-limiting examples of which are provided herein.

In accordance with various aspects of this disclosure, determining acounteracting sound to quiet an unwanted sound may depend on thelocation (or zone) at which the sound-quieting is to occur. For example,comparing the example environments 200 and 300 shown in FIGS. 2 and 3,even for an exact same unwanted sound, a different cancellation signalis likely (e.g., due to different respective transfer functions (e.g.,as determined with the method 400 of FIG. 4), due to different roomgeometries, different distances between loudspeaker(s) and the quietedlocation, etc. Accordingly, location information may be beneficial.

Block 510 may, for example, comprise determining in which of a set ofpredetermined locations the sound-quieting operation is desired. Forexample, in a scenario in which a finite set of sound-quieting scenarioshave been defined and/or calibrated, block 510 may comprise selectingfrom the finite set. For example, referring to FIGS. 1-3, in a scenarioin which the office scenario of FIG. 2 and the bedroom scenario of FIG.3 are the only two sound-quieting scenarios in which the system has beenprepared to operate, block 510 may comprise determining whether thelocation to be quieted is the zone proximate the desk 208 or the zoneproximate the head of the bed 308.

Also for example, in the office scenario 200 shown in FIG. 2, the systemmay be calibrated to quiet sound at a plurality of locations (or zones)within the room 170. For example, a calibration procedure (e.g., likethat of FIG. 4) may be performed at a plurality of locations within theroom 170 (e.g., at the desk 208 in front of a computer, in front of aportion of the desk 208 used for paperwork, at a reading chair away fromthe desk, etc.). In such an example scenario, block 510 may compriseselecting the location within the room 170 to which the user 209 isclosest.

Block 510 may also, for example, comprise determining an exact userlocation. For example, in an example scenario in which the system hasbeen set up (e.g., calibrated) at a plurality of locations (e.g., in aregular pattern like a grid, in an irregular pattern comprisinglocations of particular importance, etc.), an exact user location may beutilized by other method blocks to interpolate between the plurality oflocations. In such a manner, sound-quieting operation may be performedbetween locations at which the system has been calibrated.

Block 510 may comprise determining or tracking user location in any of avariety of manners. For example, block 510 may comprise utilizing anarray of sensors to determine or track user location. Such sensors may,for example, be integrated with a loudspeaker and/or loudspeaker systemimplementing one or more of the aspects of the method 500 (e.g.,included on or within a loudspeaker enclosure, controller enclosure,etc.). Also for example, such sensors may generally be associated withanother system (e.g., a home security system, premises-based wirelesscommunication network, home automation system, etc.) that iscommunicatively coupled to an audio system implementing one or more ofthe aspects of the method 500. For example, an audio system thatgenerally operates to present audio (e.g., audio) content to a user maybe integrated with such other systems to leverage their user trackingcapabilities. Non-limiting examples of such user-tracking and/orinterfacing with other systems are provided in U.S. application Ser. No.14/725,904, filed May 29, 2015, titled “Multi-zone Media System andMethod for Providing Multi-zone Media;” U.S. application Ser. No.14/726,019, filed May 29, 2015, titled “System and Method for ProvidingUser Location-based Multi-zone Media;” U.S. application Ser. No.14/726,109, filed May 29, 2015, titled “System and Method for Selectingand Providing Zone-Specific Media;” and U.S. application Ser. No.14/752,505, filed Jun. 26, 2015, titled “System and Method forIntegrating a Home Media System and Other Home Systems;” the contents ofeach of which are hereby incorporated herein by reference in theirentirety.

Block 510 may comprise tracking user location utilizing any of varietyof types of sensors. For example, block 510 may comprise determininguser location based on (e.g., based at least in part on, based in parton, or based only on) information from a motion sensor (e.g., active,passive, etc.), heat or IR sensor (e.g., detecting user's body heat),light sensor (e.g., detecting when a light has been turned on, whenlight to the light sensor has been interrupted by a passing body, etc.),vibration sensor (e.g., detecting structural vibrations due to a userwalking by), sound sensor (e.g., detection of nearby noise, voicedetection, voice recognition, voice identification, voice or sound-basedtriangulation, etc.), operation of home control mechanisms (e.g., lightswitches, water control valves, thermostats, appliances, blinds, ceilingfans, etc.), door operation (e.g., interior door, exterior door, garagedoor, refrigerator door, washer/dryer door, cabinet door, dresserdrawers, etc.), operation of home electronic devices (e.g., computers,stereos, video games, home entertainment systems, intercom systems,etc.). For example, loudspeaker location and sensor location may beknown, so user proximity detected by a particular sensor may be tied toone or more loudspeakers or sensors (e.g., individually, logicallygrouped into a set of loudspeakers or audio zone, etc.).

Block 510 may also, for example, comprise determining user locationbased at least in part on one or more signals received from a personalelectronic device (e.g., a carryable and/or wearable device, a smartphone, a smart watch, eyeglasses, a wireless earpiece, a wearablependant, a bracelet, a ring, etc.). For example, a receiver at a knownlocation detecting a wireless signal may determine how close the user isto the receiver based, at least in part, on signal strength. Also forexample, a plurality of receivers receiving a wireless signal atrespective signal strengths may be utilized to triangulate the user'sposition. Further for example, a personal electronic device worn orcarried by the user may have its own position-determining capability(e.g., GPS, cellular triangulation, Wi-Fi triangulation, etc.), and thencommunicate the user's location within the premises to the audio system(e.g., to a loudspeaker, central controller, or other equipmentimplementing one or more aspects of the example method 500).

Various aspects of the method 500 (and the other methods discussedherein) may comprise processing user location to make various audiopresentation decisions. Information of user location may, for example,be utilized in an absolute sense (e.g., a user is at or near aparticular location or zone). Also for example, monitored user locationmay be utilized to estimate user travel trajectory for variousanticipatory operational aspects, for example quieting an unwanted soundat a location to which movement of the user is anticipated.

Block 510 may, for example, comprise determining or tracking location ofa single user or multiple users. For example, in an exampleimplementation in which a system implementing the method 500 isproviding sound-quieting services to a plurality of users, block 510 maycomprise tracking the location of each user and providing respectivecounteracting sound to a respective location or zone associated witheach user.

Various aspects of this disclosure may also depend on user identity. Forexample, whether sound cancellation and/or masking is presently desired,the criteria for selecting between utilizing sound cancellation and/ormasking to mitigate (or address) unwanted sound, volume thresholds fortriggering countermeasures for unwanted sound, etc., may beuser-dependent. For example, the manner in which unwanted sound ishandled by the system for the example environment 200 of FIG. 2 maydepend on the identity of the user 209. Also for example, the manner inwhich unwanted sound is handled by the system for the exampleenvironment 300 of FIG. 3 may depend on the identity of the user 309and/or the presence or absence of other users. Accordingly, variousaspects of this disclosure also comprise determining user identity aswell as location.

Various sensors may also be utilized to determine not only userlocation, but also the identity of the user. For example, in an examplescenario utilizing personal electronic devices to track a user, apersonal electronic device may be associated with a respective userthereof. Also for example, in a scenario in which audio sensors areutilized to track a user, a user's voice may be utilized to identify theuser (e.g., utilizing voice recognition and/or identificationtechnology). Additionally for example, in a scenario in which avibration sensor is utilized to identify the user, the user may beidentified by the magnitude of the vibration (e.g., due to user mass),the gate of the vibration (e.g., due to stepping cadence), etc.

Further for example, assumptions regarding user identification and/orlocation may be utilized to identify a user (e.g., assumptions based ona predicted movement pattern for a known user, assumptions based on theidentification of a user at an immediately adjacent sensor or area,assumptions based on a user being the only user detected in a premisesthus far, etc.). As an example, a user detected yet not explicitlyidentified in an audio presentation zone may be presumptively identifiedas the user that was just identified in an immediately adjacent audiopresentation zone. Also for example, a user detected yet not explicitlyidentified in front of the television during Monday night football maybe presumptively identified as the user that is typically identified atthat location at that time. Additionally for example, a user laying on aparticular side of the master bed may be identified as the user thatgenerally lies at that position. Further for example, a user sitting ata desk may be identified as the user that generally works at the desk.

In general, block 510 may comprise identifying a location, for example alocation at which an unwanted sound is to be quieted. Block 510 may alsocomprise determining or tracking user location and/or identity.Accordingly, the scope of this disclosure should not be limited bycharacteristics of any particular manner of determining a locationand/or an identity.

The example method 500 may, at block 520, comprise identifying anunwanted sound at the location (e.g., as identified at block 510). Block520 may comprise identifying an unwanted sound at the location in any ofa variety of manners, non-limiting examples of which are presentedherein.

Block 520 may, for example, comprise receiving an unwanted sound with asound sensor of a user-wearable or carryable device. An example of suchoperation is presented in the example environment 200 of FIG. 2. Such adevice may, for example, comprise a smart phone, a mobile phone, aBluetooth earpiece, a smart watch, smart eyewear, a gaming headset, afitness monitoring device, etc. Also for example, block 520 may comprisereceiving the unwanted sound at one or more sound sensors near thelocation of interest (e.g., mounted to a well, mounted to or sitting onfurther, at a loudspeaker with sound sensing capability, etc.). Forexample the one or more sound sensors may be positioned within a tenthor eight of a wavelength of sound that is to be cancelled, but suchproximity is not necessary. For example, the one or more sound sensorsmay be co-located with one or more loudspeakers utilized to generate thecancellation signal (or sound). Many examples of such devices areprovided herein and/or in the references that have been incorporatedherein by reference. As shown in the example scenarios 200 and 300 shownin FIGS. 2 and 3, the unwanted sound may be received at one sound sensoror at a plurality of sound sensors.

Note that the unwanted sound may, for example, be received as the onlysound (e.g., when no wanted sound exists and/or when no cancellationsignal is being produced by the system), but may generally be receivedalong with other sounds. For example, block 520 may comprise receivingthe unwanted sound superimposed on other sounds (e.g., superimposed onwanted music, superimposed on sound having frequency content in bandsnot cancelled by the system, superimposed on cancellation signalproduced by the system, etc.).

The receipt of sound generally, including wanted and/or unwanted sound,is shown graphically at FIG. 6 at sound sensor 605, amplifier 610, andA/D converter 615. Note that FIG. 6 does not include all componentsinvolved in receiving the sound. There may, for example, be additionalfiltering prior to the A/D converter 615. Also note that variouscomponents shown in FIG. 6 may be arranged in a different order. The A/Dconverter 615 may, for example, sample the sound for at least aparticular duration, depending on the frequency range of concern. In anexample scenario in which frequency components of concern includefrequencies down to 40 Hz, a sampling duration of 50 ms may be used.Such sampling may, for example, be performed continuously so that anadequately sampled waveform to analyze is always available.

Block 520 may, for example, comprise isolating (or separating) unwantedsound from the received sound. For example, any of a variety of filters(e.g., as shown by the filter 622 or any other filter) may be utilizedto separate the unwanted sound.

In an example scenario in which the unwanted sound to be canceled isbelow 200 Hz (or below 300 Hz or below 400 Hz, for example), block 520may comprise removing sound at frequencies higher than 200 Hz (e.g.,utilizing a low pass filter such as the low pass filter 622 shown inFIG. 6). In such a scenario, even though there may also be wanted soundbelow 200 Hz, at least a substantial portion of wanted sound may beremoved from the sound cancelling operation. Note that the frequencyboundaries for sound cancellation might not be sharp cut-offfrequencies. For example, there may be a frequency band in which theeffectiveness of sound cancellation wanes as a function of frequency, asopposed to a sharp boundary.

Additionally, in an example scenario in which the system knows thecharacteristics of the wanted sound (e.g., in a scenario in which theaudio system canceling the unwanted sound is the same system as theaudio system producing the wanted sound, for example music, or isintegrated with such audio system), block 520 may comprise subtractingfrom the received sound various components associated with the wantedsound. For example as discussed in the discussion of FIG. 4, a transferfunction relating a known sound signal to a sound received by a soundsensor may be known. Accordingly, a wanted sound caused by a knownwanted sound signal may then be determined utilizing the transferfunction and then subtracted from the received aggregate sound to leavethe unwanted sound.

In another example, block 520 may comprise utilizing a combination offiltering the received sound to remove sound components at frequencybands that cannot effectively be quieted by the system, and subtractingcomponents that are determined to be wanted components.

Block 520 may also comprise identifying a received sound as unwantedbased on a user command. For example, a user working at a desk may tell(or otherwise indicate to) the system to quiet the user's workspace. Atthat point, the block 520 may comprise receiving sound andcharacterizing all of the received sound as unwanted sound.

As discussed herein, one or more sound sensors may be located at thelocation or zone to be quieted (e.g., the example scenario 200 shown inFIG. 2). In such case, the sound received by such sound sensors isgenerally directly indicative of the sound being presented to thelocation. Also as discussed herein, one or more sound sensors may belocated away from the location or zone to be quieted (e.g., the examplescenario 300 shown in FIG. 3, for example if the location of interest isthe user's head). For example, in a first example scenario, the one ormore sound sensors may be located at least one fourth or half wavelengthof the lower bound of the passband of the sound to be cancelled awayfrom the location of interest. In a second example scenario, the one ormore sound sensors may be located substantially farther than one fourthor half wavelength of the lower bound of the passband of the sound to becancelled from the location or zone to be quieted. In such examplescenarios, block 520 may comprise calculating the sound presented to thelocation. For example, if a first sound sensor receives the sound, asecond sound sensor receives the sound, and the spatial relationshipbetween the sound sensors and the location of interest is known, thesound presented to the location may be determined. For example, throughcomparison of the sound received by the first and second sensors, adirection (or angle of incidence) may be determined for the sound (e.g.,based on differential phase, the speed of sound, etc.). Based on thedirection and the spatial relationship between the sound sensors and thelocation, the phasing of the sound presented to the location may bedetermined. Additionally, amplitude of the sound may also be estimated(e.g., by averaging, weighted averaging, etc.). In general, so long asthe transfer function from the sensor(s) to the quiet zone location isknown, the sound sensors may be close to the zone to be quieted and/orfar from the zone to be quieted.

In general, block 520 may comprise identifying an unwanted sound at thelocation (e.g., as identified at block 510). Accordingly, the scope ofthis disclosure should not be limited by characteristics of anyparticular manner of identifying an unwanted sound at a location (orzone).

The example method 500 may, at block 530, comprise determining acancellation signal (or counteracting sound) to quiet the unwanted sound(e.g. as identified at block 520) at the location (e.g., as identifiedat block 510). Block 530 may comprise determining the cancellationsignal in any of a variety of manners, non-limiting examples of whichare provided herein. Block 530 may, for example, comprise utilizing anyor all of the signal processing blocks shown in aggregate block 620 atFIG. 6. Block 530 may, for example, comprise determining thecancellation signal as the inverse of the unwanted sound (ordisturbance). For example, the output of the filter 622 may include adisturbance passband (or band of sound that comprises a substantialamount of unwanted sound). The disturbance passband may then, forexample, be inverted by the inverter 625 to, at least in part, determinethe cancellation signal.

For various reasons, block 530 may comprise attenuating (or reducing theamplitude) of one or more components of the cancellation signal. Suchattenuation may, for example, result in less than ideal cancellation ofthe unwanted sound, but may provide for increased system stabilityand/or may reduce the occurrence and/or magnitude of imperfectcancellation signals experienced by a user at the location. An exampleof an attenuator circuit 626 is provided at FIG. 6. The attenuator 626may, for example, perform a 6-10 dB attenuation relative to idealcalculated magnitude levels.

In general, block 530 may comprise determining a cancellation signal (oranti-noise signal, or counter-sound) to quiet the unwanted sound (e.g.as identified at block 520) at the location (e.g., as identified atblock 510). Accordingly, the scope of this disclosure should not belimited by characteristics of any particular counteracting sound or byany particular manner of determining a counteracting sound.

The example method 500 may, at block 540, comprise generating thecounteracting sound (e.g., as determined at block 530). Block 540 maycomprise generating the counteracting sound in any of a variety ofmanners, non-limiting examples of which are presented herein.

For example, as discussed herein, there is a relationship, for examplethat may be represented as a transfer function, between a sound signalgenerated by electronics and a sound detected at a location. Once thisrelationship is known, a sound signal that will cause a desired sound tobe provided to the location may be determined.

In the example provided at FIG. 6, a digital signal (or discrete timesignal) representative of the determined cancellation signal is providedto an inverse transfer function block 630, which may, for example,comprise an inverse transform block depending on the manner in which thecalibration transform was formed (e.g., at the method 400 of FIG. 4).The output of block 630 may, for example, comprise a digital signal thatwill cause the desired cancellation signal to be presented to thelocation (e.g., after being converted to an electrical signal to drive aloudspeaker, after the loudspeaker generates the sound, after the soundtravels through the environment to the location, etc.). The digitalsignal may be converted to an analog signal by the D/A converter 635,amplified by amplifier 640, and provided to drive the speaker 650.

Note that block 540 may, for example, comprise selecting a loudspeaker(or array of speakers) to utilize for the sound cancellation. Suchselecting may comprise any of a variety of characteristics, non-limitingexamples of which are presented herein. For example, block 540 maycomprise selecting a loudspeaker that has been assigned to a zone orlocation to be quieted, for example as part of a calibration procedure.Also for example, block 540 may comprise selecting a loudspeaker that isclosest to a zone or location to be quieted and/or that has thecapability to adequately provide cancellation sound.

In general, block 540 comprises generating the counteracting sound(e.g., as determined at block 530). Accordingly, the scope of thisdisclosure should not be limited by characteristics of any particularcancellation signal or by any particular manner of generating acancellation signal.

The example method 500 may, at block 595, comprise continuing executionof the method 500. Such continued execution may comprise any of avariety of characteristics, non-limiting examples of which are presentedherein. For example, block 595 may comprise looping execution flow backup to any of the previous blocks of the example method 500 and/or to anyflow diagram block discussed herein.

In an example scenario, block 595 may comprise looping execution flow ofthe method 500 back up to block 520. Block 520 may comprise receiving anaggregate sound comprising the unwanted sound and the cancellationsignal generated at block 540. Block 530 may then, for example, analyzethe aggregate sound to determine the cancellation effectiveness of thecancellation signal generated at block 540. Block 520 may then compriseadjusting the determined counteracting sound. For example, the aggregatesound may be analyzed just as the unwanted sound alone was previouslyanalyzed to determine the existence of significant sound components tocancel. Block 530 may then adjust the determined counteracting sound toaddress remaining significant components of unwanted sound. Executionflow of the method 500 may thus continue to converge to a best solutionfor a stable unwanted sound, and may also thus track a changing unwantedsound with sound cancellation that adapts to changes in the unwantedsound.

Though the example method 500 was generally presented as utilizing asingle speaker to output the cancellation signal, it should be notedthat a plurality of speakers (e.g., of an array of speakers in a singlehousing, of an array of speakers that are relatively close to each otherin a acoustic sense, etc.) may be utilized instead of a single speaker.For example, a plurality of speakers may be utilized in a scenario inwhich directionality of the cancellation signal is beneficial. Asufficient number of speakers and sensors may be employed to detectdirectionality (origin) of an objectionable noise source's wave frontsand to substantially cancel them by employing commonly acceptedpractices of acoustic array processing, for example up to a frequencywhere the center-to-center spacing of sensors and speakers (cancellingsources) is less than or equal to one half of one acoustic wavelength.

Additionally, the example sound cancellation scenarios shown in FIGS. 2and 3 and discussed herein showed a primary source of unwanted soundthat is positioned outside of the premises. It should be understood thatsources of unwanted sound may also be located within the premises and/orwithin a same room as a zone to be quieted. Examples of unwanted noisemay, for example, include an exercise bike, a treadmill, HVAC equipmentor vents, a fan, etc. The primary source of unwanted sound may furtherbe closer to the zone to be quieted than the secondary source ofcancellation sound.

In an example scenario in which a primary source of unwanted noise iscloser to the zone to be quieted than the secondary source ofcancellation sound, a predictive algorithm, for example based on thepast characteristics of the primary source for generating thecancellation signal, may be employed. Allowances for processing time mayfurther require even greater spatial discrepancies of primary andsecondary sources unless a predictive algorithm is employed. As anexample, when a primary source exhibits high periodicity, its soundradiation characteristics may be predicted and some portion of itsassociated radiated sound may be substantially canceled even when thesecondary source is substantially further away from the targeted quietzone than the primary source. High periodicity may, for example, beexhibited by treadmills, exercise bicycles, cooling fans, homeappliance, or other sources that are rotational in nature whose soundradiation is thereby highly cyclical.

Additionally, sound radiation from secondary sources may be timedrelative to that of primary sources such that incident sound waves fromboth reach the target location coincidentally. Calibration proceduresmay, for example, determine secondary-source timing data appropriatelyfor a range of possible target locations. Further, when an array ofmultiple secondary sources are employed to cancel sound at a targetlocation, each element of the array's contribution to the overallcancellation wave may be such that it reaches the target coincidentallywith that of neighboring array elements' cancellation signals.

The discussion to this point has generally focused on cancellation ofunwanted sound in a quiet zone. There are, however, cases in whichunwanted sound may be cancelled or attenuated over a wide area. Forexample, special cases for installed in-room disturbances such as HVACsystems may be configured in a manner that attenuates radiated noiseover a wide coverage area as opposed to a single or even discretemultiple quiet zones. Dedicated single-channel broad-band feedforwardadaptive noise cancellation (ANC) systems may, for example, utilize anadaptive LMS (least mean squares) algorithm that, for example, utilizesboth a reference microphone located near the known source of unwantedsound (e.g., near a motor/blower chamber of an HVAC unit, for examplewithin an HVAC air duct) and an error (or feedback) microphone locatednear an outlet for the unwanted sound (e.g., an air duct's outlet vent).The secondary source (sound cancelling loudspeaker), with which theerror microphone may be integrated, may be beneficially located near theoutlet for the unwanted sound (e.g., near the air duct's outlet vent)also.

Utilization of an error (or feedback) microphone may be beneficial in avariety of scenarios. While an “a priori” feedforward approach thatassumes stationary room acoustics, constant sound speed and variousother pertinent characteristics that affect noise cancellationeffectiveness has been taken through most of this disclosure, afeedback-oriented approach, for example one that relies on the physicalpresence of an error microphone placed near the targeted quiet zone, maybe implemented (e.g., instead of the feedforward approach and/or incombination with the feedforward approach). The error microphone may,for example, be integrated into wearable electronics (e.g., asmartphone, a smart watch, a pendant, eyeglasses, clothing, etc.) ormay, for example, comprise a stand-alone (wired or wireless) microphone,the output of which may be transmitted to a digital signal processinghub, for example via an appropriately minimally lossless, low latencymeans. In a feedback-based implementation, characteristics of thedigital filter, for example its coefficients, may continuously adapt,for example to minimize (e.g., in a least mean squared sense) thetime-averaged signal at the error microphone.

For illustrative clarity, most of this disclosure has focused onquieting a single zone, for example at a user's head while working orsleeping. It should be noted, however, that a quieting solution maycomprise performing zone quieting for a plurality of zones, some ofwhich may be close to each other (e.g., nearby pillows for sleeping orresting users). In a scenario in which quieting a first zone willsubstantially impact quieting of a second one or more zones, a costfunction may be utilized. For example, various aspects of thisdisclosure comprise attenuating an objectionable primary source's soundlevels over a broader area and/or within multiple discrete quiet zonesby minimizing a suitable “cost function”, such as for example the sum ofsquared sound pressure values, at a number of discrete (e.g., real orvirtual, the latter via previous calibration) microphone locations. Forexample, in the absence of consideration for locations outside of theprimary quiet zone, noise levels could escalate above that which theywould attain outside of the primary quiet zone. The cost function may,for example, provide a compromise solution between a plurality of quietzones and/or generally over a large area.

The discussion generally to this point has focused on utilizingcancellation techniques to quiet an unwanted sound. In variousscenarios, other techniques for counteracting unwanted sound may beutilized instead of or in addition to sound cancellation. Such othertechniques may, for example, comprise sound masking (e.g., generatingother sounds to mask the unwanted sound, for example, sounds of oceanwaves, rain showers, or brooks, white or pink noise, etc.).

For example, in an example scenario in which unwanted sound comprisessubstantial energy in frequency bands for which sound cancellation doesnot work well, another technique (e.g., sound masking) may be utilizedinstead of sound cancellation or in addition to sound cancellation.

FIG. 7 is a flow diagram of an example method 700 for counteracting anunwanted sound, in accordance with various aspects of the presentdisclosure. The method 700 may, for example, share any or allcharacteristics with other example methods discussed herein (e.g., withregard to FIGS. 4-6 and other discussions). FIG. 9, which is a diagram900 of example signal processing for quieting an unwanted sound and/ormasking an unwanted sound, in accordance with various aspects of thepresent disclosure, will be referred to during the discussion of FIG. 7.The example system 900 of FIG. 9 may, for example, share any or allcharacteristics with the system 600 shown in FIG. 600 (e.g., with regardto like-numbered elements).

The example method 700 may begin executing at block 705. The examplemethod 700 may begin executing in response to any of a variety of causesor conditions. Block 705 may, for example, share any or allcharacteristics with blocks 405 and 505 of the example methods 400 and500 shown in FIGS. 4 and 5 and discussed herein.

The example method 700 may, at block 710, comprise identifying acountermeasure strategy to utilize against unwanted sound. Block 710 maycomprise identifying the countermeasure strategy in any of a variety ofmanners, non-limiting examples of which are provided herein.

For example, block 710 may comprise identifying the countermeasurestrategy based, at least in part, on user preferences. The userpreferences may, for example, be expressed presently by the user. Forexample, the user may use a present tactile input or voice input tospecify “cancel sound,” “mask sound,” “cancel and mask sound,” etc. Thespecified preference might only apply to a present unwanted sound, butmay also be stored in a user profile, for example as a default mode ofsound countermeasure operation for the user. For example, a user mayspecify that the user only wants sound cancellation to be utilized, onlywants sound masking to be utilized, wants both sound cancellation andsound masking to be utilized, wants the system to decide which of soundcancellation and/or sound masking (or other countermeasures) to utilize,etc.

Block 710 may, for example, comprise identifying the countermeasurestrategy based, at least in part, on characteristics of the unwantedsound. For example, block 710 may comprise identifying thecountermeasure strategy based, at least in part, on frequency content ofthe unwanted sound. For example, if the unwanted sound has substantialfrequency content (e.g., at least a threshold level) in a frequency bandin which sound cancellation is effective but not in other bands, thenblock 710 might comprise incorporating only sound cancellation into theoverall sound countermeasure strategy. Also for example, if the unwantedsound has substantial frequency content in a frequency band in whichsound cancellation is relatively ineffective but not in other bands,then block 710 may comprise incorporating only sound masking into theoverall sound countermeasure strategy. Additionally, for example, if theunwanted sound has substantial frequency content in a frequency band inwhich sound cancellation is effective, and also has substantialfrequency content in a frequency band in which sound cancellation isrelatively ineffective, then block 710 may comprise incorporating bothsound cancellation and sound masking into the overall soundcountermeasure strategy. In other words, if the bandwidth of theunwanted sound covers includes frequency bands in which soundcancellation is effective and in which sound cancellation isineffective, then block 710 may comprise incorporating both soundcancellation and sound masking into the overall sound countermeasurestrategy.

Block 710 may also, for example, comprise identifying the countermeasurestrategy based, at least in part, on overall volume of the unwantedsound. For example, if the unwanted sound is so loud that masking willbe ineffective, then block 710 may include sound cancellation in thecountermeasure strategy (e.g., instead of sound masking or in additionto sound masking). Also for example, if the unwanted sound is at arelatively low volume at which masking will be effective, then block 710may include sound masking in the countermeasure strategy (e.g., insteadof sound cancellation or in addition to sound cancellation). Further forexample, if the unwanted sound is at a volume at which both soundcancellation and sound masking will be effective, then block 710 mayinclude both sound cancellation and sound masking in the countermeasurestrategy.

In general, block 710 may comprise identifying a countermeasure strategyto utilize against unwanted sound. Accordingly, the scope of thisdisclosure should not be limited by characteristics of any particularcountermeasure strategy or any particular manner of identifying ordetermining a countermeasure strategy.

The example method 700 may, at block 720, comprise directing executionflow of the method 700. If block 710 determined that the overallcountermeasure strategy includes sound cancellation, then block 720 maydirect execution flow of the method 700 to block 725. If, however, block710 determined that the overall countermeasure strategy does not includesound cancellation, then block 720 may direct execution flow of themethod 700 to block 730.

The example method 700 may, at block 725, comprise determining acancellation sound (or counteracting sound or counter-sound) to cancelthe unwanted sound at the location. Block 725 may, for example, shareany or all characteristics with blocks 510, 520, and/or 530 of theexample method 500 shown in FIG. 5 and discussed herein.

The example method 700 may, at block 730, comprise directing executionflow of the method 700. If block 710 determined that the overallcountermeasure strategy includes sound masking, then block 730 maydirect execution flow of the method 700 to block 735. If, however, block710 determined that the overall countermeasure strategy does not includesound masking, then block 730 may direct execution flow of the method700 to block 740.

The example method 700 may, at block 735, comprise determining a maskingsound to utilize to mask the unwanted sound. Block 735 may comprisedetermining the masking sound in any of a variety of manners,non-limiting examples of which are provided herein.

Block 735 may, for example, comprise determining the masking soundbased, at least in part, on user input. For example, a user maypresently specify a masking sound by command (e.g., a tactile command, avoice command, etc.). Additionally, a user profile may includespecification of the masking sound, which block 735 may then identify(e.g., always, as a default absent an additional user command, etc.).Further for example, block 735 may comprise determining the maskingsound based on characteristics of the unwanted sound to be masked. Forexample, in an example scenario in which a first masking sound masks afirst type of unwanted sound (e.g., from a jet engine) better than asecond masking sound, block 735 may comprise selecting the first maskingsound when analysis of the unwanted sound indicates that the unwantedsound matches the characteristics of jet engine noise. In an examplescenario in which a user (e.g., as part of a user profile for the user)indicates that the system is to select the masking sound, block 735 mayselect the masking sound without present interaction with the user. Theuser may then, for example, alter the selection with a user command.Block 735 may, for example, be performed by the adaptive maskinggenerator 910 shown in FIG. 9.

Block 735 may also, for example, comprise determining a gain setting ofthe determined masking sound. For example, block 735 may comprisedetermining the gain setting to be a particular level greater than thevolume of the unwanted sound (e.g., a particular number of decibels (orSPLs) higher, etc.). For example, relative to the unwanted sound to bemasked, it may be beneficial for the masking sound to be appreciablylouder than the unwanted sound and to reflect an appropriate spectralbalance. For example, by monitoring the sound (or noise) to be cancelledand/or masked, appropriate gain and masking program settings (e.g.,pseudo random pink or white noise with appropriate magnitude shapingthat adaptively responds to the spectrum of external, background noisesthat are to be masked in a smooth, non-obtrusive manner with minimallatency) may be optimized.

In general, block 735 may comprise determining a masking sound toutilize to mask the unwanted noise. Accordingly, the scope of thisdisclosure should not be limited by characteristics of any particularmasking sound or by any particular manner of determining a maskingsound.

The example method 700 may, at block 740, comprise directing executionflow of the method 700. If block 710 determined that the overallcountermeasure strategy includes generation of a countermeasure sound(e.g., includes sound cancelling, sound masking, etc.), then block 740may direct execution flow of the method 700 to block 745. If, however,block 710 determined that the overall countermeasure strategy does notinclude a countermeasure sound, then block 740 may direct execution flowof the method 700 to block 795.

The example method 700 may, at block 745, comprise generating thecountermeasure sound, for example as determined at block 725 and/orblock 735. Block 745 may, for example, share any or all cancellationsignal generation characteristics with the example method 500 (e.g.,block 540). Also for example, block 745 may comprise generating themasking signals that cause the loudspeaker(s) to output the determinedmasking sound.

Block 745 may comprise generating the countermeasure sound in any of avariety of manners. As shown in FIG. 9, a summing circuit 920 mayreceive a cancellation signal from the D/A converter 635 and/or amasking signal from the adaptive masking generator 910. The summercircuit 920 may combine the cancellation signal and/or masking sound forpresentation to the amplifier 640. Though not shown, note that thecircuit 900 may comprise a cross-over filter (e.g., at the input(s) tothe summing circuit 920) if needed to establish (or ensure) separaterespective passbands for the cancellation signal and the masking signal.For example, a cancellation passband may generally include the band forwhich cancellation operation is utilized, and a masking passband maygenerally include the band for which masking operation is utilized. Thecancellation passband and masking passband may, for example, beimmediately adjacent.

The example method 700 may, at block 795, comprise continuing execution.Such continued execution may comprise any of a variety ofcharacteristics, non-limiting examples of which are presented herein.For example, block 795 may comprise looping execution flow back up toany of the previous blocks of the example method 700 and/or to any flowdiagram block discussed herein.

Any or all of the functionality discussed herein may be performed by anaudio output device (e.g., a loudspeaker) or a plurality of audio outputdevices working together. Also as discussed herein, any or all of thefunctionality discussed herein may be performed by an audio systemcontroller, an audio server, etc. An example audio system component(e.g., a controller, a smart loudspeaker, a combination thereof, etc.)will now be presented. Note also that the various modules, or portionsthereof, discussed with regard to the audio system component 800 of FIG.8 may be dispersed throughout a distributed system. Also for example, apremises or home may comprise an audio system component (e.g., acontroller) for the entire premises or home, an audio zone (e.g., anarea or room, portion of a room, etc.) may comprise a respective audiosystem component (e.g., a controller) for the audio zone, etc.Additionally for example, all of the receiving, analyzing, determining,generating, user interfacing, etc. discussed herein may be performed byelements located in a single housing (e.g., an audio box with soundquieting capability).

FIG. 8 is a block diagram of an example audio system component 800(e.g., an audio system controller and/or other component), in accordancewith various aspects of the present disclosure. The example audio systemcomponent 800 may, for example, operate to or be operable to perform anyor all of the functionality discussed herein (e.g., with regard to theexample methods 400, 500, 600, and 700 illustrated in FIGS. 4-7 anddiscussed herein, with regard to the example environments 100, 200, and300 illustrated in FIGS. 1-3 and discussed herein, with regard to themethods and systems incorporated herein by reference, etc.). The audiosystem component 800 may, for example, comprise any one or more of avariety of audio system components. For example, the audio systemcomponent 800 may comprise a home or premises audio controller, aloudspeaker, a video display with audio capability, etc., but the scopeof this disclosure is not limited thereto. The audio system component800 may, for example, share any or all characteristics with the mediacontroller 111 and/or other components of the environment 100.

The audio system component 800 may, for example, comprise a power supplymodule 805. The power supply module 805 may, for example, compriseelectrical circuitry operable to receive and/or prepare electrical powerfor utilization by the other modules of the audio system component 800.The power supply module 805 may, for example, comprise an A/C powermodule adapted for plugging into a premises power outlet and/or fordirect integration into the A/C power system of a premises (e.g., ahome, campus, outdoor area associated therewith, etc.). The power supplymodule 805 may also, for example, be operable to receive and/or prepareelectrical power from a power-over-Ethernet (POE) system. The powersupply module 805 may additionally, for example, be operable to receiveand/or prepare battery power (e.g., manage battery operation for powersupply, recharging, etc.). The power supply module 805 may also, forexample, be operable to provide electrical power (e.g., via Ethernet orother wiring) to other media devices (e.g., to other loudspeakers),sensors, controllers, etc.

The example audio system component 800 may also, for example, comprise auser interface module 810. The user interface module 810 may, forexample, be operable to perform any or all of the user interfacefunctionality discussed herein. For example, the user interface module810 may be operable to perform the user and/or output functionalitydiscussed herein with regard to at least the example method 400illustrated in FIG. 4, the example method 500 illustrated in FIG. 5, theexample method 600 illustrated in FIG. 6, and the example method 700illustrated in FIG. 7.

For example, the user interface module 810 may comprise or manage anyone or more of a variety of sensors for user input. For example, theuser interface module 810 may comprise a touch sensor and associatedcircuitry for processing touch inputs. The touch sensor for user touchinput may, for example, comprise a touch pad, touch screen, heat sensor,capacitive sensor, piezo-resistive sensor, piezo-electric sensor, lightsensor, MEMS inertial sensor, a mechanical switch, etc. The touch inputmay, for example, comprise a tap input (e.g., single-tap, double-tap,n-tap, etc.). The touch input may, for example, comprise a touch inputon a graphical user interface feature being presented to the user on atouch screen. The touch input may also, for example, comprise a swipeinput (e.g., for adjustment of media presentation characteristics, likevolume, etc.). Also for example, the user interface module 810 maycomprise an audio sensor (e.g., a microphone, speaker with sounddetection capability, etc.) and associated circuitry for processingaudible inputs (e.g., voice commands).

The user input sensors may, for example, be included on or within anenclosure of the audio system component 800 (e.g., in a single ormultiple enclosure system). Additionally for example, the sensors may bephysically separate from and/or outside of an enclosure of the audiosystem component 800. As discussed herein, for example, touch sensorsand/or microphones may be incorporated into switch plates, door frames,doors, etc., and thus need not necessarily be physically integrated withthe audio system component 800 or any portion thereof. In such exampleimplementations, the sensors may be hardwired with the audio systemcomponent 800 and/or may wirelessly communicate with the audio systemcomponent 800. In a wireless communication scenario, the user interfacemodule 810 may utilize wireless communication capability of thecommunication interface module 830 discussed herein to communicatewirelessly with one or more sensors.

The user interface module 810 may also, for example, comprise any one ormore of a variety of user output devices (e.g., for providing audioand/or video media to a user, for providing audio feedback to a user,for providing visual output feedback to a user, etc.). For example, theuser interface module 810 may operate to provide an output to the userto indicate the mode of operation in which the audio system component800 is operating, to indicate a source of the audio output beingpresented to the user, to indicate the audio output characteristics ofthe audio currently being presented to the user, to output user inputfeatures (e.g., graphical user interface features), etc.

The user interface module 810 may further, for example, operate tointerface with a remote control device (e.g., a dedicated remote controldevice, a smart phone, etc.). For example, the user interface module 810may utilize the communication interface module 830 to communicate withthe user's smart phone.

The example audio system component 800 may additionally, for example,comprise one or more communication interface modules 830. Thecommunication interface module(s) 830 may, for example, be operable toperform any or all of the communication functionality discussed herein(e.g., in the discussions of FIGS. 1-7). Such communicationfunctionality may, for example, comprise communicating with othersystems or devices (e.g., other loudspeakers or displays, controllers,media servers, etc.). Such communication functionality may, for example,comprise communicating information regarding general system operation,media information, sensor information, security information, homeautomation information, user input and/or output information, zoneidentification information, user identification information, mediacontent, etc.

The communication interface module(s) 830 may, for example, be operableto establish, maintain, and utilize communication links with other audioor media devices (e.g., with loudspeakers, with video monitors, with anaudio controller, with a local audio server within a premises or homeover a local area network, with a remote media server outside of apremises or home over the Internet, cable, landline and/or othernetworks, with remote control devices, smart phones, smart watches,etc.). The communication interface module 830 may, for example, beoperable to communicate over wired, wireless, or optical links.

The communication interface module(s) 830 may, for example, be operableto interface with a wired and/or wireless local area network (LAN),personal area network (PAN), wide area network (WAN), etc. Thecommunication interface module(s) 830 may, for example, be operable tointerface with a telecommunication network (e.g., cellular, landline,satellite, etc.), a television network (e.g., cable, satellite, etc.),etc. The communication interface module(s) 830 may, for example, beoperable to communicate utilizing any of a variety of standard and/orproprietary communication protocols (e.g., Wi-Fi, Ethernet, Bluetooth,near field, 4G, 5G, LTE, MoCA, 802.15, etc.).

The communication interface module(s) 830 may, for example, be operableto communicate with a security system (e.g., a home security system).For example, in the various example implementations discussed herein,the communication interface module(s) 830 of the audio system component800 may be operable to communicate with a security system controller orother security system component, for example to utilize sensorcapability of a security system to determine user location and/oridentity, to identify and/or characterize unwanted sound, etc.

The communication interface module(s) 830 may, for example, be operableto communicate with an automation system (e.g., a home automationsystem). For example, in the various example implementations discussedherein, the communication interface module(s) 830 of the audio systemcomponent 800 may be operable to communicate with a home automationsystem controller or other home automation system component, for exampleto utilize sensor capability of a home automation system to determineuser location and/or identity, to identify and/or characterize unwantedsound, etc.

The communication interface module(s) 830 may, for example, be operableto communicate with an audio (or other media) server system (e.g., alocal home audio server system, a remote audio server system remote fromthe premises or home, etc.). For example, in the various exampleimplementations discussed herein, the communication interface module(s)830 of the audio system component 800 may be operable to communicatewith various audio servers, for the general presentation of audio (orother media) to a user.

The example audio system component 800 may additionally, for example,comprise an audio output module 815. The audio output module 815 may,for example, be operable to perform any or all of the audio (or media)output functionality discussed herein (e.g., with regard to the examplemethods 400, 500, 600 and 700 shown in FIGS. 4-7 and discussed herein;with regard to the example environments 100, 200, and 300 shown in FIGS.1-3 and discussed herein, with regard to the example methods and/orsystems incorporated herein by reference, etc.). Such audio outputfunctionality may, for example, comprise the output of sounds forcancellation and/or masking of unwanted sounds. Such audio outputfunctionality may also, for example, comprise generally performing audiooutput functionality for the audio system (e.g., performing generalaudio generating, for example for audio streaming, generating audio fromlocal home-based or remote media servers, etc.). Also for example, asdiscussed herein, at least a portion of the audio output functionalitymay, for example, comprise generating audio received from other systemsdifferent from the audio system (e.g., audio received at a home audiosystem from a home or premises security system, audio received from ahome or premises automation system, etc.).

The example audio system component 800 may further, for example,comprise one or more on-board sensors 820. Various examples of suchsensors, for example with regard to user I/O, were discussed herein withregard to the user interface module 810. Many examples of the on-boardsensors 820 are presented herein. For example, the on-board sensors 820may comprise a motion detector, light detector, gas sensor, microphoneor other audio sensor, vibration sensor, infrared sensor, camera, scale,static sensor, touch pad, retinal scanner, fingerprint sensor, biometricdetector, etc. The on-board sensors 820 may, for example, be attached toand/or incorporated within a housing of the audio system component 800.Also, as discussed herein, in addition to the on-board sensors 820, theaudio system component 800 may also comprise sensors that are off-boardthe component 800 (e.g., not attached to and/or incorporated within ahousing of the component 800) but which are communicatively coupled tothe component 800 (e.g., mountable and/or wearable and/or carryablesound sensors, etc.).

The example audio system component 800 may, for example, comprise asensor manager module 825. The sensor manager module 825 may, forexample, be operable perform any or all of the sensor-relatedfunctionality discussed herein (e.g., with regard to the example methods400, 500, 600, and 700 shown in FIGS. 4-7 and discussed herein; withregard to the example environments 100, 200, and 300, shown in FIG. 1-3and discussed herein; with regard to the example methods and/or systemsincorporated herein by reference, etc.).

For example, the sensor manager module 825 may be operable to interfacewith on-board sensors 820 and/or with off-board sensors (e.g., sensorsthat are not attached to and/or located with a housing of the audiosystem component 800). For example, when a reading from a sensor isdesired, the sensor manager module 825 may interface with the sensor toacquire the desired reading. Also for example, in another examplescenario, the sensor manager module 825 may operate to asynchronouslyreceive sensor measurement information from a sensor (e.g., on aninterrupt basis).

The sensor manager module 825 may, for example, be operable to interfacewith systems external to the media system (e.g., home security systems,home automation systems, etc.). For example, in an example scenario, thesensor manager module 825 of the audio system component 800 may beoperable to utilize the communication interface module 830 tocommunicate with a security system, with a home automation system, etc.In such an example scenario, the sensor manager module 825 may, forexample, be operable to interface with such systems for the utilizationof their sensor capabilities.

Note that the sensor manager module 825 may also be operable tointerface with sensors of systems external to the audio system of theaudio system component 800. For example, the sensor manager module 825may utilize the communication interface module 830 to communicate with asensor of a home security system, either via a controller of thesecurity system or directly via a communication network 205 andby-passing the security system controller. Similarly, the sensor managermodule 825 may utilize the communication interface module 830 tocommunicate with a sensor of a home automation system, either via acontroller of the home automation or directly via the communicationnetwork 205 and by-passing the home automation system controller.

The example audio system component 800 may also, for example, comprise acalibration module 840. The calibration module 840 may, for example, beoperable to perform any or all of the calibration functionalitydiscussed herein (e.g., with regard to the example method 400illustrated in FIG. 4 and discussed herein, etc.).

The example audio system component 800 may additionally, for example,comprise a location identification module 850. The locationidentification module 850 may, for example, be operable to perform anyor all of the location identification functionality discussed herein(e.g., with regard to the example method 500 of FIG. 5, for exampleblock 510 thereof, etc.).

The example audio system component 800 may additionally, for example,comprise an unwanted sound identification module 860. The unwanted soundidentification module 860 may, for example, be operable to perform anyor all of the unwanted sound identification functionality discussedherein (e.g., with regard to the example method 500 of FIG. 5, forexample block 520 thereof, with regard to the example method 600 of FIG.6, for example blocks 605, 610, and 615 thereof, etc.).

The example audio system component 800 may additionally, for example,comprise a cancellation signal identification module 870. Thecancellation signal identification module 870 may, for example, beoperable to perform any or all of the counteractive sound identificationfunctionality discussed herein (e.g., with regard to the example method500 of FIG. 5, for example block 530 thereof, with regard to the examplemethod 600 of FIG. 6, for example blocks 622, 624, 625, 626, and 628thereof, with regard to the example method 700 of FIG. 7, for exampleblocks 725 and 735 thereof, etc.).

The example audio system component 800 may additionally, for example,comprise a cancellation signal generation module 880. The cancellationsignal generation module 880 may, for example, be operable to performany or all of the counteractive sound generation functionality discussedherein (e.g., with regard to the example method 500 of FIG. 5, forexample block 540 thereof, with regard to the example method 600 of FIG.6, for example blocks 630, 635, 640, and 650 thereof, with regard to theexample method 700 of FIG. 7, for example block 745 thereof, etc.).

The example audio component 800 may, for example, comprise a processor890 (e.g., at least one) and a memory 895 (e.g., at least one). Any orall of the functionality or associated modules discussed herein may, forexample, be implemented in hardware and/or implemented using acombination of hardware and software (e.g., a processor operating inaccordance with software instructions stored on a non-transitorycomputer-readable medium). For example, the processor 890 may operate inaccordance with software instructions stored in the memory 895 toimplement all or any part of the modules discussed herein. The processor890 may, for example, comprise one or more of a general-purposemicroprocessor, a digital signal processor (DSP), an applicationspecific integrated circuit (ASIC), a microcontroller, etc. The memory895 may, for example, comprise one or more of a non-volatile and/orvolatile memory. Note that the memory 895 may also be utilized forstoring media content, media presentation characteristics, user profileinformation, etc. The memory 895 may, for example, be on-board oroff-board the processor 890.

Though the example audio system component 800 is generally discussedherein by example as an audio system controller, the scope of thisdisclosure should not be limited by characteristics of such audio systemcontroller example. For example, the component 800 may also beimplemented as a component of a system external to an audio system. Forexample, the component 800 or any portion thereof may be implemented asa security system component, an automation system component, and/or anyof a variety of other types of system components.

In summary, various aspects of this disclosure provide a system andmethod for quieting and/or otherwise counteracting unwanted sound. Whilethe foregoing has been described with reference to certain aspects andembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the disclosure. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the disclosure without departing from its scope.Therefore, it is intended that the disclosure not be limited to theparticular embodiment(s) disclosed, but that the disclosure will includeall embodiments falling within the scope of the appended claims.

What is claimed is:
 1. An audio system comprising: at least one moduleoperable to, at least: characterize, utilizing at least a firstmicrophone positioned at a location, a relationship between a soundsignal used to cause a loudspeaker to output an output sound and theoutput sound received at the location; identify, utilizing at least asecond microphone and not the first microphone, an unwanted sound at thelocation; determine, based at least in part on the determinedcharacterization, a cancellation signal that, when used to cause theloudspeaker to output a counteracting sound, will quiet the unwantedsound at the location; and generate the cancellation signal to cause theloudspeaker to output the counteracting sound.
 2. The audio system ofclaim 1, wherein the at least one module is operable to characterize therelationship by, at least in part, operating to determine a transferfunction.
 3. The audio system of claim 1, wherein the at least onemodule is operable to characterize the relationship by, at least inpart, operating to: generate a test stimulus signal to cause theloudspeaker to output a test stimulus; receive the test stimulus at thelocation; and analyze the test stimulus signal and the received teststimulus to determine a functional relationship between the teststimulus signal and the received test stimulus.
 4. The audio system ofclaim 3, wherein the test stimulus signal comprises a pseudo-randomnoise signal comprising a pink noise signal.
 5. The audio system ofclaim 3, wherein the test stimulus signal comprises a swept frequencysignal comprising frequencies in a range up to at least twice a quietingpassband of the audio system.
 6. The audio system of claim 1, whereinthe at least one module is operable to determine the cancellation signalby, at least in part, operating to determine the cancellation signalbased, at least in part, on the identified unwanted sound and thecharacterized relationship.
 7. The audio system of claim 6, wherein theat least one module is operable to determine the cancellation signal by,at least in part, operating to: determine an inverse of an unwantedsound signal that represents the unwanted sound; determine thecancellation signal based, at least in part, on the determined inverse.8. The audio system of claim 1, wherein the at least one module isoperable to determine the cancellation signal by, at least in part,operating to, independent of user input, set a magnitude of thecancellation signal to a level below that determined for idealcancellation.
 9. An audio system comprising: at least one moduleoperable to, at least: identify a location; identify an unwanted soundat the location; identify, based at least in part on the identifiedlocation, a loudspeaker to utilize to quiet the unwanted sound;determine a counteracting sound that, when output by the loudspeaker,will quiet the unwanted sound at the location; and output thecounteracting sound at the loudspeaker.
 10. The audio system of claim 9,wherein the at least one module is operable to identify the location by,at least in part, operating to receive an input from a user that isunrelated to audio presentation.
 11. The audio system of claim 9,wherein the at least one module is operable to identify the locationbased, at least in part, on performing sound-based triangulation on asound made by the user.
 12. The audio system of claim 9, wherein the atleast one module is operable to identify the location based, at least inpart, on a wireless signal received from a personal electronic devicethat is independent of the audio system.
 13. The audio system of claim9, wherein the at least one module is operable to identify the unwantedsound at the location by, at least in part, operating to receive theunwanted sound using at least one sound sensor positioned at thelocation.
 14. The audio system of claim 13, wherein the at least onemodule is operable to determine a direction of the unwanted sound, andto determine the counteracting sound based at least in part on thedetermined direction.
 15. The audio system of claim 9, wherein the atleast one module is operable to identify the unwanted sound at thelocation by, at least in part, operating to receive the unwanted soundusing at least one sound sensor positioned at a distance away from thelocation at least one fourth of a wavelength of a lower bound of afrequency band of sound to be counteracted.
 16. The audio system ofclaim 15, wherein the at least one module is operable to determine adirection of the unwanted sound, and to determine a counteracting soundbased at least in part on the determined direction.
 17. The audio systemof claim 16, wherein: the at least one module is operable to identifythe unwanted sound at the location by, at least in part, operating toreceive the unwanted sound using at least a first sound sensorpositioned away from the location and a second sound sensor positionedaway from the location, wherein the first sound sensor and the secondsound sensor are positioned at a distance away from the location atleast one fourth of a wavelength of a lower bound of a frequency band ofsound to be canceled; and the at least one module is operable todetermine the direction of the unwanted sound by, at least in part,operating to determine the direction based at least in part on theunwanted sound received at each of the first and second sound sensors.18. An audio system comprising: at least one module operable to, atleast: identify an unwanted sound to counteract; analyze the identifiedunwanted sound; select, based at least in part on the analysis of theidentified unwanted sound and independent of user input, between aplurality of different types of countermeasure strategies forcounteracting the unwanted sound; and implement the selected strategy.19. The audio system of claim 18, wherein the plurality of differenttypes of countermeasure strategies comprises: a first countermeasurestrategy comprising performing sound cancellation; and a secondcountermeasure strategy comprising performing sound masking with a noisesignal.
 20. The audio system of claim 18, wherein the plurality ofdifferent types of countermeasure strategies comprises: a firstcountermeasure strategy comprising performing sound cancellation; asecond countermeasure strategy comprising performing sound masking; anda third countermeasure strategy comprising performing sound cancellationand sound masking on a same sound to be counteracted.
 21. The audiosystem of claim 20, wherein the third countermeasure strategy comprisessimultaneously performing sound masking and sound cancellation ondifferent respective portions of the same sound to be counteracted. 22.The audio system of claim 20, wherein the third countermeasure strategycomprises performing sound masking on a first frequency range of thesame sound to be counteracted and performing sound cancellation on asecond frequency range, different from the first frequency range, of thesame sound to be counteracted.